How to retrieve annotated instance from Guice's injector?
Let's say I have a module:
Module extends AbstractModule
{
@Override
protected void configure()
{
bind(String.class).
annotatedWith(Names.named("annotation")).
toInstance("DELIRIOUS");
}
}
and I want to test the module and check if it injects the right value in a String
field annotated with Names.named("annotation")
without having a class and a field but obtaining the value directly from the injector:
@Test
public void test()
{
Injector injector = Guice.createInjector(new Module());
// THIS IS NOT GOING TO WORK!
String delirious = injector.getInstance(String.class);
assertThat(delirious, IsEqual.equalTo("DELIRIOUS");
}
Solution 1:
injector.getInstance(Key.get(String.class, Names.named("annotation")));
Solution 2:
I'm using the following method
public <T> T getInstance(Class<T> type, Class<? extends Annotation> option) {
final Key<T> key = Key.get(type, option);
return injector.getInstance(key);
}
for this. In general, you still have the problem of creating the annotation instance, but here Names.named("annotation")
works.